1. Field of the Invention
The present invention relates to orthopaedic devices for the stabilization and control of a human knee joint along several axes and has as its primary purpose the stabilization of the knee joint which has been injured. Stabilization and control is achieved in such a manner as to permit the user relative freedom in the normal use of the bones while, at the same time, permitting control over the joint so as to optimize healing.
The human knee is acknowledged as one of the weakest joints in the body. It is the articulating joint between the thigh and calf muscle groups which support the body's weight while walking or running, and it is held together primarily by two small but powerful ligaments, the anterior and posterior cruciate ligaments. Knee instability arising out of cartilage damage, ligament strain and other such causes is relatively commonplace since the knee joint is subjected to significant loads during the course of almost any kind of physical activity requiring the use of the legs. Devices for adding support and strength to the knee joint have been known at least since the very early Sears and Roebuck catalogs, which provided elasticized support members intended to circumscribe the joint to apply a squeezing pressure which results in a "feeling" of additional support even though that support may be physiologically minimal.
While the public has been sports-minded for years, it was not until the late 1960's, with a great increase in the volume of televised professional sports, and very highly paid athletes, and, in particular, contact sports such as football, basketball and soccer, that sports medicine, as a specialized field, evolved. Until that time, knee braces typically consisted of two sets of links connected by a pivot pin which were disposed on either side of the knee and sewn into an elasticized sleeve which was slipped over the knee joint like an elastic sock so that the pivot pins were disposed on either side of the knee. Such devices afforded virtually no protection to an athlete engaged in a contact sport, or in a sport where there is a large amount of stress placed on the knee joint due to running, jumping, pivoting and the like.
2. Survey of the Prior Art
Perhaps one of the first and most highly publicized breakthroughs, or at least advances in knee orthoses, occurred when the Lennox Hill brace was developed to protect the knees of Joe Namath, then one of the highest paid athletes in any sport. Several deficiencies in the Lennox Hill design have been recognized, however, and sports medicine people have spawned a plethora of other braces in attempts to improve knee stabilization. The designs include single and double pivot designs, although the double pivot design available typically includes a center link with pivot points at each end, and with the center link being axially aligned with the femur and tibia. Among such braces are included the model 4521 offered by Orthopedic Systems, Inc. of Hayward, Calif., and the polyaction knee orthosis offered by Scott Orthopedic Labs in Denver, Colo. Still another, called c.t.i. brace, is offered by Innovation Sports of Irvine, Calif.
The patent art also offers several exemplars of efforts to stabilize injured knee joints, and among them are the following patents:
Foster, U.S. Pat. No. 4,353,361; Gardner, U.S. Pat. No. 3,799,158; Deibert, U.S. Pat. No. 4,271,831; Horne, U.S. Pat. No. 3,779,654; Taylor, U.S. Pat. No. 3,902,482; Gromes, U.S. Pat. No. 1,336,695; Buring, et al., U.S. Pat. No. 4,409,689; Almedia, U.S. Pat. No. 4,139,002; and Meierhofer, U.S. Pat. No. 2,379,538.
The bulk of the prior art offerings comprise a variety of braces ranging from very simple to quite complex mechanical joints, all of which have a unity of intent, i.e., stabilization of an injured knee. Some of the braces are intended to protect and stabilize particular injuries and others are more general in their application. As will become apparent from the following detailed description of a preferred embodiment of the present invention, however, none of these prior efforts accomplished the high degree of stabilization with relative simplicity offered by the present invention.